1. Field of the invention The present invention relates to an image pick-up device suited for one shot image pick-up, particularly a picture recording device with improved efficiency and able to provide improved picture quality by use of a solid image sensor in combination with a shutter.
2. Description of the Prior Art
In video cameras using a solid state image sensor such as a CCD, the storage, the transfer, and the read out of the image are carried out at a certain predetermined period.
Consequently, the storage time is constant so that the quality of the picture degrades depending on adverse conditions of an object such as when the object has a quick motion or high brightness.
Even in a conventional frame transfer type CCD, for example, a strong light falls incident on the light sensing part while the charge formed in the light sensing part is transferred to the storage portion, and the light is superposed on the charge during the transfer as noise over a wide range. This causes a smear phenomenon and degrades the picture quality.
In an interline transfer type CCD, although the vertical shift register is shaded, light of long wave length falls obliquely upon the substrate under the vertical shift register to produce minority carriers so that there is a possibility of smear in the same way. Particularly, in a interline transfer type CCD, the charge in the vertical register is normally transferred 1 bit every horizontal period of the TV signal so that the above problem is very likely to occur.
Also known is a device in which an overflow drain gate beside each picture element cuts the charge in the light sensing part to control the storage timing and the storage time of the photo electrons and to transfer the stored charge periodically.
Such a device makes it possible not only to read out the signal at the TV rate but also to optionally set the storage time. However, if the storage time is shortened, the S/N decreases substantially as described and a smear results during the charge transfer.
Further, a conventional video camera is designed for continuous photography and a satisfactory image signal cannot bo obtained if only one shot is desired to be photographed.
Also, when the image pick-up device is provided with a video monitor, it is impossible to confirm the one shot picture image.